(Incazelo efingqiwe)Phakathi kwabasebenzisi abasebenzisa amakhulu-ama-valve embulunga yobubanzi empilweni yansuku zonke.
Phakathi kwabasebenzisi abasebenzisa amavalvu eglobhu amakhulu-ububanzi empilweni yansuku zonke, abantu bavame ukubika inkinga, okungukuthi, amavalvu eglobhu amakhulu-awudayamitha avame ukuba nzima ukuvala uma esetshenziswa emithonjeni yezindaba enomehluko omkhulu wokucindezela, njengesitimu nokuphakama. - amanzi okucindezela. Phakathi kwabasebenzisi abasebenzisa ama-valve okumisa ama-diameter amakhulu nsuku zonke, abantu bavame ukubika inkinga, okungukuthi, ama-valve okumisa ama-diameter amakhulu ngokuvamile kunzima ukuwavala uma esetshenziswa emithonjeni yezindaba enomehluko omkhulu wokucindezela, njengesitimu. futhi high-amanzi okucindezela. Indlela yokuyivala ngamandla, kuhlale kutholakala ukuthi kuzoba nokuvuza, futhi kunzima ukuvala. Isizathu sale nkinga sibangelwa ukwakheka kwe-valve kanye nokuntuleka kwe-torque yezinga lomkhawulo womuntu.
Ukuhlaziywa kwezizathu zobunzima bokuvula nokuvala amavalvu amakhulu-esikali
Amandla okukhipha avundlile okugcina omuntu omdala omaphakathi angama-60-90kg, kuya ngezimo ezihlukene.
Ngokuvamile, indlela yokugeleza kwe-valve yokuvala - yokuvala yakhelwe ukuba ibe ngaphansi futhi iphume phezulu. Lapho umuntu evala i-valve, umzimba womuntu uphusha isondo lesandla liye phezulu ukuze i-valve disc ibheke phansi ukuze ivaleke. Ngalesi sikhathi, inhlanganisela yamandla amathathu idinga ukunqotshwa, okungukuthi:
1) I-axial thrust Fa;
2) Ukungqubuzana phakathi kokupakisha kanye ne-valve stem Fb;
3) Ukungqubuzana kokuxhumana kwe-Fc phakathi kwesiqu se-valve ne-valve core
Isamba sezikhathi singu-∑M=(Fa+Fb+Fc)R
Kuyabonakala ukuthi ubukhulu be-outlet bukhulu, bukhulu amandla we-axial thrust. Uma iseduze nesimo esivaliwe, amandla okuphonswa kwe-axial acishe asondele ekucindezelweni kwangempela kwenethiwekhi yamapayipi (ngenxa ye-P1-P2≈P1, P2=0)
Isibonelo, uma ivalvu yokumisa ye-DN200 isetshenziswa epayipini lesitimu eliyi-10bar, into yokuqala kuphela evala amandla okuphusha i-axial Fa=10×πr2=3140kg, futhi amandla okujikeleza avundlile adingekayo ukuze kuvalwe aseduze nokukhishwa kwe-axial circumferential of a umzimba womuntu ojwayelekile. Umkhawulo wamandla, ngakho-ke kunzima kakhulu kumuntu oyedwa ukuvala ngokuphelele i-valve ngaphansi kwezimo ezinjalo.
Yiqiniso, ezinye izimboni zisikisela ukuthi ama-valve anjalo kufanele afakwe ohlangothini oluphambene, okuxazulula inkinga yobunzima bokuvala, kodwa inkinga yobunzima ekuvuleni ngemva kokuvalwa iye yavela.
Ukuhlaziywa kwezizathu zokuthi kungani amavalvu eglobhu amakhulu-ububanzi ethambekele ekuvuzeni kwangaphakathi
Amavalvu okumisa amakhulu-ububanzi ngokuvamile asetshenziswa kumabhoyela, amasilinda amancane, amapayipi amakhulu esitimu, njll. Lezi zindawo zinezinkinga ezilandelayo:
1) Ngokuvamile, umehluko wengcindezi endaweni yokuphuma kubhayela mkhulu kakhulu, ngakho izinga lokugeleza kwesitimu nalo likhulu, futhi ukuguguleka nokulimala endaweni evalekayo nakho kukhulu. Ukwengeza, ukusebenza kahle komlilo we-boiler akukwazi ukuba ngu-100%, okuzokwenza ukuthi umusi ekuphumeni kwe-boiler ube nomthamo omkhulu wamanzi, okungenzeka kubangele ukulimala kwe-cavitation kanye ne-cavitation endaweni yokuvala i-valve.
2) Ku-valve yokuvala eduze nendawo yokuphuma kubhayela kanye nesilinda, ngoba isitimu esiphuma kubhayela sinezinto ezishisa kakhulu, ngesikhathi sokugcwala, uma ukuthambisa amanzi kubhayela kungekuhle kakhulu. , ingxenye ye-asidi ngokuvamile izoba nemvula. Izinto ze-alkali zizodala ukugqwala nokuguguleka endaweni evalayo; ezinye izinto ezicwebezelayo zingase zinamathele endaweni evalekayo futhi zicwebezele, okubangele ukuthi ivalvu yehluleke ukuvala ngokuqinile.
I-3) I-valve yokungena kanye ne-outlet yamasilinda, ngoba inani le-steam ngemva kwe-valve ngezinye izikhathi likhulu noma lincane ngenxa yezidingo zokukhiqiza nezinye izizathu, kulula ukubangela ukukhanya, i-cavitation nezinye izenzakalo lapho izinga lokugeleza lishintsha kakhulu. I-valve seal surface idala imiphumela elimazayo njengokuguguleka kanye ne-cavitation.
4) Ngokujwayelekile, lapho kuvulwa ipayipi elikhulu-elikhulu, ipayipi lidinga ukushisisa ngaphambili, futhi inqubo yokushisa kuqala idinga ukugeleza okuncane kwesitimu ukuze kudlule, ukuze ipayipi lifudumale kancane futhi ngokulinganayo ngezinga elithile, futhi i-valve yokumisa ingavulwa ngokugcwele ukuze kugwenywe ipayipi elisheshayo Ukwanda ngokweqile okubangelwa ukushisa, kulimaze ingxenye yengxenye yokuxhuma. Kodwa-ke, kule nqubo, ukuvulwa kwe-valve kuvame ukuba kuncane kakhulu, okwenza izinga lokuguguleka libe likhulu kakhulu kunomphumela ovamile wokusetshenziswa, futhi kunciphisa kakhulu impilo yesevisi yendawo yokuvala i-valve.
Izixazululo zokuvula nokuvalwa okunzima kwamavalvu -
1) Okokuqala, kutuswa ukukhetha ivalvu-evalwe-evaliwe ukuze ugweme ukumelana nokungqubuzana kwevalvu ye-plunger kanye nevalvu yokupakisha futhi wenze ukushintsha kube lula.
I-2) I-valve core kanye nesihlalo kufanele senziwe ngezinto ezinokumelana nokuguguleka okuhle kanye nezakhiwo zokugqoka, njenge-Stellite cemented carbide.
I-3) Kunconywa ukuba wamukele isakhiwo se-valve flap kabili ukuze ugweme ukuguguleka ngokweqile ngenxa yokuvuleka okuncane, okuzothinta impilo yesevisi kanye nomphumela wokuvala. Uma ivaliwe, kuhlale kutholakala ukuthi kuzoba nokuvuza, futhi kunzima ukuvala. Isizathu sale nkinga sibangelwa ukwakheka kwe-valve kanye nokuntuleka kwe-torque yezinga lomkhawulo womuntu.
Ukuhlaziywa kwezizathu zobunzima bokuvula nokuvala amavalvu amakhulu-esikali
Amandla okukhipha avundlile okugcina omuntu omdala omaphakathi angama-60-90kg, kuya ngezimo ezihlukene.
Ngokuvamile, indlela yokugeleza kwe-valve yokuvala - yokuvala yakhelwe ukuba ibe ngaphansi futhi iphume phezulu. Lapho umuntu evala i-valve, umzimba womuntu uphusha isondo lesandla liye phezulu ukuze i-valve disc ibheke phansi ukuze ivaleke. Ngalesi sikhathi, inhlanganisela yamandla amathathu idinga ukunqotshwa, okungukuthi:
1) I-axial thrust Fa;
2) Ukungqubuzana phakathi kokupakisha kanye ne-valve stem Fb;
3) Ukungqubuzana kokuxhumana kwe-Fc phakathi kwesiqu se-valve ne-valve core
Isamba sezikhathi singu-∑M=(Fa+Fb+Fc)R
Kuyabonakala ukuthi ubukhulu be-outlet bukhulu, bukhulu amandla we-axial thrust. Uma iseduze nesimo esivaliwe, amandla okuphonswa kwe-axial acishe asondele ekucindezelweni kwangempela kwenethiwekhi yamapayipi (ngenxa ye-P1-P2≈P1, P2=0)
Isibonelo, uma ivalvu yokumisa ye-DN200 isetshenziswa epayipini lesitimu eliyi-10bar, into yokuqala kuphela evala amandla okuphusha i-axial Fa=10×πr2=3140kg, futhi amandla okujikeleza avundlile adingekayo ukuze kuvalwe aseduze nokukhishwa kwe-axial circumferential of a umzimba womuntu ojwayelekile. Umkhawulo wamandla, ngakho-ke kunzima kakhulu kumuntu oyedwa ukuvala ngokuphelele i-valve ngaphansi kwezimo ezinjalo.
Yiqiniso, ezinye izimboni zisikisela ukuthi ama-valve anjalo kufanele afakwe ohlangothini oluphambene, okuxazulula inkinga yobunzima bokuvala, kodwa inkinga yobunzima ekuvuleni ngemva kokuvalwa iye yavela.
Ukuhlaziywa kwezizathu zokuthi kungani amavalvu eglobhu amakhulu-ububanzi ethambekele ekuvuzeni kwangaphakathi
Amavalvu okumisa amakhulu-ububanzi ngokuvamile asetshenziswa kumabhoyela, amasilinda amancane, amapayipi amakhulu esitimu, njll. Lezi zindawo zinezinkinga ezilandelayo:
1) Ngokuvamile, umehluko wengcindezi endaweni yokuphuma kubhayela mkhulu kakhulu, ngakho izinga lokugeleza kwesitimu nalo likhulu, futhi ukuguguleka nokulimala endaweni evalekayo nakho kukhulu. Ukwengeza, ukusebenza kahle komlilo we-boiler akukwazi ukuba ngu-100%, okuzokwenza ukuthi umusi ekuphumeni kwe-boiler ube nomthamo omkhulu wamanzi, okungenzeka kubangele ukulimala kwe-cavitation kanye ne-cavitation endaweni yokuvala i-valve.
2) Ku-valve yokuvala eduze nendawo yokuphuma kubhayela kanye nesilinda, ngoba isitimu esiphuma kubhayela sinezinto ezishisa kakhulu, ngesikhathi sokugcwala, uma ukuthambisa amanzi kubhayela kungekuhle kakhulu. , ingxenye ye-asidi ngokuvamile izoba nemvula. Izinto ze-alkali zizodala ukugqwala nokuguguleka endaweni evalayo; ezinye izinto ezicwebezelayo zingase zinamathele endaweni evalekayo futhi zicwebezele, okubangele ukuthi ivalvu yehluleke ukuvala ngokuqinile.
I-3) I-valve yokungena kanye ne-outlet yamasilinda, ngoba inani le-steam ngemva kwe-valve ngezinye izikhathi likhulu noma lincane ngenxa yezidingo zokukhiqiza nezinye izizathu, kulula ukubangela ukukhanya, i-cavitation nezinye izenzakalo lapho izinga lokugeleza lishintsha kakhulu. I-valve seal surface idala imiphumela elimazayo njengokuguguleka kanye ne-cavitation.
4) Ngokujwayelekile, lapho kuvulwa ipayipi elikhulu-elikhulu, ipayipi lidinga ukushisisa ngaphambili, futhi inqubo yokushisa kuqala idinga ukugeleza okuncane kwesitimu ukuze kudlule, ukuze ipayipi lifudumale kancane futhi ngokulinganayo ngezinga elithile, futhi i-valve yokumisa ingavulwa ngokugcwele ukuze kugwenywe ipayipi elisheshayo Ukwanda ngokweqile okubangelwa ukushisa, kulimaze ingxenye yengxenye yokuxhuma. Kodwa-ke, kule nqubo, ukuvulwa kwe-valve kuvame ukuba kuncane kakhulu, okwenza izinga lokuguguleka libe likhulu kakhulu kunomphumela ovamile wokusetshenziswa, futhi kunciphisa kakhulu impilo yesevisi yendawo yokuvala i-valve.
Izixazululo zokuvula nokuvalwa okunzima kwamavalvu -
1) Okokuqala, kutuswa ukukhetha ivalvu-evalwe-evaliwe ukuze ugweme ukumelana nokungqubuzana kwevalvu ye-plunger kanye nevalvu yokupakisha futhi wenze ukushintsha kube lula.
I-2) I-valve core kanye nesihlalo kufanele senziwe ngezinto ezinokumelana nokuguguleka okuhle kanye nezakhiwo zokugqoka, njenge-Stellite cemented carbide.
I-3) Kunconywa ukuba wamukele isakhiwo se-valve flap kabili ukuze ugweme ukuguguleka ngokweqile ngenxa yokuvuleka okuncane, okuzothinta impilo yesevisi kanye nomphumela wokuvala.
Isikhathi sokuthumela: 2020-11-10 00:00:00